Sooty mangabey
Cercocebus atys

TAXONOMY

Suborder: Haplorrhini
Infraorder: Simiiformes
Superfamily: Cercopithecoidea
Family: Cercopithecidae
Subfamily: Cercopithecinae
Genus: Cercocebus
Species: atys
Subspecies: C. a. atys, C. a. lunulatus

Other names: sooty mangabey, red-capped mangabey, white-crowned mangabey; kalalu; C. a. lunulatus: white-collared mangabey, white-naped mangabey.

Some researchers subsume C. atys under C. torquatus as a subspecies but due to consistent differences and a geographic separation between C. torquatus and C. atys populations, C. atys is elevated to its own species, with the white-naped mangabey (C. a. lunulatus) as a subspecies (Booth 1956; Groves 2001). C. a. atys is an intermediate form between C. atys and C. a. lunulatus that may be a hybrid of the two (Groves 2001).

MORPHOLOGY

Photo: Kathelijne Koops

The sooty mangabey is characterized by, and gains its name, from its pelage color, which ranges from gray to brown-gray (Groves 2001). The color is somewhat lighter on the ventral surfaces and is darker on the extremities. The face is grayish-pink with a black muzzle and ears. The long cheek whiskers are lighter than the body (Groves 2001). The subspecies C. a. lunulatus has gray-brown pelage with a white ventral area including inner limbs. It also has a black stripe on its back and the back of its head is white (Mittermeier et al. 2006). There is a high level of sexual dimorphism between males and females (McGraw 1996). Female sooty mangabeys average 5.5 kg (12.13 lb) and males average 10.2 kg (22.49 lb) (Harvey & Clutton-Brock 1985). The sooty mangabey is somewhat less sexually dimorphic than Cercocebus torquatus (Groves 2001). Maximum longevity of the sooty mangabey is 18 years (Harvey & Clutton-Brock 1985).

The species is best described as being primarily terrestrial (McGraw 1996). The vast majority of sooty mangabey movement is quadrupedal, with over 80% of locomotion being of this type (McGraw 1998). In addition, over 75% of the sooty mangabey's movement occurs terrestrially and the remainder is mostly restricted to lower levels of forest strata (McGraw 1998). Climbing and leaping by the sooty mangabey occurs only in the understory, shrub layer and on the ground (McGraw 1998). Instead of sitting directly on the ground, the sooty mangabey prefers to seek out something to sit on, including fallen branches or other items resting on the forest floor (McGraw 1996).

RANGE

The sooty mangabey is found on the west coast of Africa from Senegal to Ghana and in every coastal country between, including Burkina Faso, Côte d'Ivoire, Guinea, Guinea-Bissau, Liberia, and Sierra Leone (Struhsaker 1971; Groves 2001; Galat & Galat-Luong 2006). Other researchers place the range in the rainforests between Guinea and the Sassandra River in the Côte d'Ivoire (Rödel et al. 2002). Between the two subspecies, C. a. atys is found west of the Nzo-Sassandra river while C. a. lunulatus is found east of the river (Booth 1956). C. a. lunulatus is found only east between the Sassandra River in the Côte d'Ivoire and the Volta River in neighboring Ghana (Mittermeier 2006).

C. atys range (in red)

One of the few wild study sites of the sooty mangabey is the Taï National Park in the Côte d'Ivoire. This national park is the largest and one of the last remaining primary forests in West Africa (Range & Noë 2002). Research has been undertaken at the Taï National Park by Friederike Range, Ronald Noë, and William McGraw. In 1968 a captive group of 27 sooty mangabeys was established at the Yerkes Regional Primate Research Center in Atlanta, Georgia where it has expanded and remains under study (Bernstein 1971; Gust & Gordon 1991b).

HABITAT

The main habitat of the sooty mangabey is the West African high forest (Range & Noë 2002). In the Côte d'Ivoire at the Taï National Park, the sooty mangabey habitat is tropical moist evergreen rainforest (McGraw 1998; Range & Noë 2002). At this location the average temperature is 24°C (75.2°F) with a pair of dry seasons, one from July to August and another between November and February (McGraw 1998). The heaviest rainfall totals for the year occur in September and October (Rödel et al. 2002). Average rainfall at this study site is 1,875 mm (73.82 in) (Range & Noë 2002). Other habitats of the sooty mangabey are gallery forest and the deciduous Bissine forest which is dry with a canopy at 15m (49.31 ft) and an open understory (Struhsaker 1971; Galat & Galat-Luong 2006). The sooty mangabey is capable of living in both old growth forest and secondary forest and will choose either if available (Fimbel 1994). In addition, farmland is often utilized and inhabited by the sooty mangabey. In Ghana, the species is most often found in areas with Rhaphia palm swamps and rice farms (Booth 1979).

ECOLOGY

Sooty mangabeys do most of their moving and foraging on the ground in the forest (Rödel et al. 2002). The staples of their diet include fruits, seeds and invertebrates, with seeds making up 68% of the diet and invertebrates making up 26% (Bergmüller 1998 cited in Rödel et al. 2002). Other observations of the species place plants as a far higher proportion of what is eaten at 98.7% and animal foods at only 1.3%. Of the 98.7% plant foods, the vast majority were fruits with small minorities of leaves, flowers and miscellaneous plant parts. Of the animal foods, sooty mangabeys do not eat vertebrates and the species is almost entirely frugivorous at some locations (Booth 1979; Galat & Galat-Luong 1985). Sooty mangabeys are also regular eaters of frog-spawn from arboreal clutches surrounding ponds. They know where to look for these clutches of frog eggs and actively seek them out as a food source (Rödel et al. 2002).

Photo: Yerkes NPRC

Daily, the diurnal sooty mangabey will divide its activities between feeding, resting, social activities, traveling and foraging. Of its daily activity budget, feeding takes up 38.8%, rest 18.5%, social activities 7.9%, travel 10.3%, and foraging 24.5% (McGraw 1998). Sooty mangabey home range is estimated at 4 to 6 km² (1.54-2.32 mi²) but can be as large as 6.5 km² (2.5 mi²) (Galat & Galat-Luong 1985; McGraw unpubl. data cited in McGraw & Bshary 2002). Home ranges of sooty mangabey groups are known to overlap extensively in the wild and intergroup encounters are typified by avoidance, ignorance, or aggressive interactions (Range 2005).

The day range of the sooty mangabey is large (McGraw 1996). In captivity, patterns of daily activities emerge and are as follows. In the early morning, sooty mangabeys are very active, displaying, traveling and sexually presenting. Social contact is not prevalent at this time of day. In the late morning and early afternoon traveling decreases and social contact, grooming and play are primary activities. By the late afternoon, feeding behavior and play are prevalent with traveling increasing toward the sunset hours (Bernstein 1976).

Potential predators of the sooty mangabey in the Taï National Park are leopards, crowned hawk eagles, chimpanzees (Pan troglodytes) and humans (Zuberbühler et al. 1997; Range & Fischer 2004). Gaboon vipers as well as leopards and eagles elicit alarm calls from the sooty mangabey and thus are likely predators (Zuberbühler et al. 1999; Range & Fischer 2004). Red colobus (Piliocolobus sp.) and Diana monkeys (Cercopithecus diana) living in the same habitat as sooty mangabeys will expand their feeding niche when the mangabeys are present. This is presumably due to the ability of terrestrial sooty mangabeys to identify potential predators and undoubtedly this reduces the threat from ground predators to the other two species (McGraw & Bshary 2002).

The sooty mangabey often lives in the same habitat of a number of other primate species, although individual niches within the same habitat are often different. In the Taï Forest in the Côte d'Ivoire, sooty mangabeys are found with western black and white colobus monkeys (Colobus polykomos), red colobus (Piliocolobus sp.), olive colobus (Procolobus verus), Diana monkeys (Cercopithecus diana), Campbell's guenon (Cercopithecus campbelli) as well as other primates (McGraw 1998; Refisch & Koné 2005a).

SPECIAL NOTES

The sooty mangabey is used in biomedical AIDS research and is a natural host of the simian immunodeficiency virus (SIV), the disease from which the human immunodeficiency virus (HIV) is derived. Because it is a natural host, if infected with the virus, the sooty mangabey does not get sick and is studied in the hope that the means by which it remains healthy might be discovered and help treat or prevent the disease in humans (Silvestri 2005). In addition, sooty mangabeys are the only species in which naturally occurring leprosy has probably been transmitted from one monkey to another (Gormus et al. 1988). There is also evidence for spatial memory among the species, with individuals remembering which fruit trees which they had previously visited and whether or not the trees were more likely to carry fruit than others (Janmaat et al. 2006).

Content last modified: May 4, 2007

Written by Kurt Gron.

Cite this page as:
Gron KJ. 2007 May 4. Primate Factsheets: Sooty mangabey (Cercocebus atys) Taxonomy, Morphology, & Ecology. <http://pin.primate.wisc.edu/factsheets/entry/sooty_mangabey>. Accessed 2008 May 9.